Renormalized Perturbation Theory for Fast Evaluation of Feynman Diagrams on the Real Frequency Axis

We present a method to accelerate the numerical evaluation of spatial integrals of Feynman diagrams when expressed on the real frequency axis. This can be realized through use of a renormalized perturbation expansion with a constant but complex renormalization shift. The complex shift acts as a regu...

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Bibliographic Details
Published inarXiv.org
Main Authors Burke, M D, Grandadam, Maxence, LeBlanc, J P F
Format Paper Journal Article
LanguageEnglish
Published Ithaca Cornell University Library, arXiv.org 04.11.2022
Subjects
Feynman diagrams
Numerical integration
Perturbation theory
Physics - Strongly Correlated Electrons
Regularization
Two dimensional models
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Summary:We present a method to accelerate the numerical evaluation of spatial integrals of Feynman diagrams when expressed on the real frequency axis. This can be realized through use of a renormalized perturbation expansion with a constant but complex renormalization shift. The complex shift acts as a regularization parameter for the numerical integration of otherwise sharp functions. This results in an exponential speed up of stochastic numerical integration at the expense of evaluating additional counter-term diagrams. We provide proof of concept calculations within a difficult limit of the half-filled 2D Hubbard model on a square lattice.
ISSN:2331-8422
DOI:10.48550/arxiv.2211.02453